<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
        "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
    <title>Title</title>
</head>
<body>
{{ t1 }}
<hr>
{{ t1|safe }}
<hr>
{% autoescape off %}
{{ t1 }}
{% endautoescape %}
<hr>
字面值：<br>
{{ t2|default:'<h1>abc</h1>' }}
<br>
手动转义：{{ t2|default:'&lt;h1&gt;abc&lt;/h1&gt;' }}
</body>
</html>